Peter P Posted February 25, 2009 Share Posted February 25, 2009 Hi Guys, Now before anyone goes asking me to look at similar threads as this has been done before, NO IT HASN'T!! I have read the threads on the similarities/differences between the two engines and can see there is a good argument for both engines as they perform well in different but equally impressive ways. The thing is weight has been thrown around both in the recent article showing the Tech2 RX7 with the 1JZ VVT-i as well as other places that claim the 2JZ to be a lot heavier. The issue for me though is I cannot find a single factual record anywhere to back this up! The twin turbo setup on the 2JZ would add weight to the later 1JZ when they changed them over to the single setup as there is less involved but what would the engines way less all ancillaries?? It's more of an issue for me as I am building an RX7 track car so keeping the weight distribution and excellent handling characteristics are key to making this car work well. Now the 1JZ can be tuned to produce useable power with the correct modifications (looking at the Garrett GT4088R for the single anyway!) and can rev higher than the 2JZ. The 2JZ is tried and tested as a very capable engine that can take big power and is near enough bullet-proof and has a better and more easily available aftermarket network in terms of parts. It's also more familiar to my tuner (those who know me will know I am part of Team Garage Whifbitz) although he would happily work on either. The secondhand market shows early 1JZ engines from around £600 whilst the 2JZ unsuprisingly starts from £1,000 upwards. Cheaper isn't always better so if it means saving the pennies a bit longer then that's fine as it would give me a better engine for my project. All thoughts and opinions gratefully accepted!! And if anyone knows or can find out what the actual weight of the bare engines (I say bare but I mean: Block, Head, Oil Pan and pistons, cranks etc) is that would be a great help as well. Thanks. Pete Quote Link to comment Share on other sites More sharing options...
Thorin Posted February 25, 2009 Share Posted February 25, 2009 The 2JZ is essentially the same block, just a longer stroke isn't it? Or so I thought anyway. Quote Link to comment Share on other sites More sharing options...
bondango Posted February 25, 2009 Share Posted February 25, 2009 Id personally opt for a 1jz with r154 gearbox. 1jz is around an inch shorter in height, so you may not need the modified bonnet. R154 weighs less than the v160. Both items easy to get your hands on as`well. Getting good useable power suited for the track wont be a prob either. Gt3076r (400hp full boost by 3100rpms) or gt35R (480ish full boost by 3600rpms) both make the 1jz quite a little monster. Basic fuel system upgrade and ecu, though emanage ult. or even EM blue will work fine. cheaper can be better Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted February 25, 2009 Share Posted February 25, 2009 Wouldn't a 1.5 JZ be the all round best option here? IE the 1JZ block with a 2 JZ head? Thats a well documented instal on soarers and and MK3s Quote Link to comment Share on other sites More sharing options...
Jay_vr6 Posted February 25, 2009 Share Posted February 25, 2009 erm is it not the better flowing 1jz head on a 2jz bottom end ? Quote Link to comment Share on other sites More sharing options...
Alex Posted February 25, 2009 Share Posted February 25, 2009 erm is it not the better flowing 1jz head on a 2jz bottom end ? Yes it is. IMO you're mad to stick in Inline engine in there. You should be looking for a V that takes up less space. Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 25, 2009 Author Share Posted February 25, 2009 Wouldn't a 1.5 JZ be the all round best option here? IE the 1JZ block with a 2 JZ head? Thats a well documented instal on soarers and and MK3s The 1JZ head is allegedly supposed to offer a better flow rate than the 2JZ head but to my knowldege no bench figures have ever been documented to confirm this. The engine you are refering to is known as a 1.5JZ which is a 1JZ head on a 2JZ block. Pete Quote Link to comment Share on other sites More sharing options...
bondango Posted February 25, 2009 Share Posted February 25, 2009 (edited) erm is it not the better flowing 1jz head on a 2jz bottom end ? no one has yet to show evidence that a 1jz head flows better than a 2jz ...internet myth PS most 1.5jz's are born outta the fact that the stock bottom end has give trouple and has been replaced with a 2jz (you get to keep any goodies youve installed up above i.e. single turbo, injectors, etc etc) Edited February 25, 2009 by bondango (see edit history) Quote Link to comment Share on other sites More sharing options...
AlexM Posted February 25, 2009 Share Posted February 25, 2009 Why is it you're even considering a heavy iron block straight six over the tiny little wankel? It might make some sort of sense for a drag car, but for a track beast? I don't get it. Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted February 25, 2009 Share Posted February 25, 2009 As above. I'd be looking at a 3s-gte, or one of the chevy LS engines. The LS conversion has been done many times before on the REX, with good results (apparently) Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 25, 2009 Author Share Posted February 25, 2009 Why is it you're even considering a heavy iron block straight six over the tiny little wankel? It might make some sort of sense for a drag car, but for a track beast? I don't get it. As you may be aware we ran a 13B powered Rex in Time Attack Pro last season at the capable hands of Darren Robinson (Whifbitz Workshop Manager) which had something like 6 13B rebuilds in the course of it's life!! The reliability of the 13B is questionable at best and even with thorough maintenance, they seem to fail quite frequently and cost over £1K to rebuild!! What I want is reliability and the 13B just won't cut it i'm afraid! I had toyed with a 3S-GTE as it worked with good effect on the Top Secret Supra which would have been a heavier base car than the Rex and is pretty reliable when built properly. Another idea is the new Renesis wankel rotary found in the RX8 as to my knowledge, no one has fitted one of these in a RX7 (waits to be proven wrong!!). A lot of the issues with the 13B seem to have been ironed out in the RX8 Renesis engine as well as better apex seals etc so maybe this could work?! I think the 1JZ/2JZ would be easier as it's well documented and you can buy a kit designed specifically for the job rather than custom fabrication which we all know costs big bucks! Pete Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 25, 2009 Author Share Posted February 25, 2009 As above. I'd be looking at a 3s-gte, or one of the chevy LS engines. The LS conversion has been done many times before on the REX, with good results (apparently) As strange as I know this sounds, I couldn't bring myself to stick a yank lump in my Jap car! I hear what your saying and the Apex R33 GTS-T V8 makes a strong argument but it just doesn't look right to me!! There's also a Rex with a V8 in Time Attack (there was last season anyway) which did seem quite nippy but didn't howl like a Jap if you know what I mean! Pete Quote Link to comment Share on other sites More sharing options...
bondango Posted February 25, 2009 Share Posted February 25, 2009 getting big reliable power outta the 3S is quite expensive though, and there are so many unknowns with the engine in RWD configuration. A lot of people dont relaise that the Topsecret Supras amounst others did not run a 3SGTE, its a 503E..they look asthetically (sp) the same, but thats were the similarites endith... Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 25, 2009 Author Share Posted February 25, 2009 Id personally opt for a 1jz with r154 gearbox. 1jz is around an inch shorter in height, so you may not need the modified bonnet. R154 weighs less than the v160. Both items easy to get your hands on as`well. Getting good useable power suited for the track wont be a prob either. Gt3076r (400hp full boost by 3100rpms) or gt35R (480ish full boost by 3600rpms) both make the 1jz quite a little monster. Basic fuel system upgrade and ecu, though emanage ult. or even EM blue will work fine. cheaper can be better Thanks for this. I'd already decided on the R154 gearbox as I know they are strong and easily sourced (used to have a few MKIII Supra Turbos!) which is fine. I did the GT35R on my UK spec with good results but would prefer to go a bit bigger this time so the GT4088R which is what we are running on Steve L's Time Attack car to good effect is my prefered choice. Just wondering what the spool up and delivery will be like with half a litre less capacity as the delivery on Steve's 2JZ is nice and early and comes on strong but would a 1JZ do the same? Pete Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 25, 2009 Author Share Posted February 25, 2009 getting big reliable power outta the 3S is quite expensive though, and there are so many unknowns with the engine in RWD configuration. A lot of people dont relaise that the Topsecret Supras amounst others did not run a 3SGTE, its a 503E..they look asthetically (sp) the same, but thats were the similarites endith... Now that I didn't know! Just confirms what I thought after pricing up a MR2 Turbo as a track car and getting some quotes from Rogue for a half descent power figure...... big £££££! Pete Quote Link to comment Share on other sites More sharing options...
AlexM Posted February 25, 2009 Share Posted February 25, 2009 As you may be aware... I didn't know you had anything to do with whifbitz, so no I had no idea. Pauls posts gave the impression that the 13B was pretty solid, and you guys had hammered it all season without issue - I guess I have misunderstood then? Do you not feel the extra weight of the straight 6 will destroy the RX7s handing advantage and weight balance? (It's a genuine question, as I've only ever seen speculation). If there's a guide for the 1JZ/2JZ and a 'kit' available, would that make the lighter and shorter 1UZ a possibility? I'd certainly like to see the conversion possibilities on one, always fancied a Rex but the Wankels reputation and thirst continuously put me off. Quote Link to comment Share on other sites More sharing options...
AlexM Posted February 25, 2009 Share Posted February 25, 2009 Just come across this thread on Supraforums, doesn't say a great deal but has a few pictures. Quote Link to comment Share on other sites More sharing options...
bondango Posted February 25, 2009 Share Posted February 25, 2009 well a 4082 on a 1jz see's 1bar boost around 4600rpms, so with a .68 arse the 4088 would be the same (knock 200rpms of for the R). But a .68 arse will run out of breath by 6700. With the 1jz you can play too 8000rpms, but to play with that power band up there you'll need a set of decent cams. A 4088r with a 1.19AR will get you great high end power or even a 4094R with a .72Ar if you want to trade it for a little lag. For instant power a gt3582r will see you a bar of boost by around 3200rpms I have shit loads of compressor map plots i done for the 1jz somewhere, though its the real world were these things count Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 26, 2009 Author Share Posted February 26, 2009 well a 4082 on a 1jz see's 1bar boost around 4600rpms, so with a .68 arse the 4088 would be the same (knock 200rpms of for the R). But a .68 arse will run out of breath by 6700. With the 1jz you can play too 8000rpms, but to play with that power band up there you'll need a set of decent cams. A 4088r with a 1.19AR will get you great high end power or even a 4094R with a .72Ar if you want to trade it for a little lag. For instant power a gt3582r will see you a bar of boost by around 3200rpms I have $#@! loads of compressor map plots i done for the 1jz somewhere, though its the real world were these things count If you can dig them out i'd really appreciate it mate! What cams would you recommend? Something like HKS 264 for both intake and exhaust?? Apart from ARP head bolts, is there anything else engine wise that needs uprating? Obviously a GT4088R can give up to 700/800HP but the max figure I seem to find everywhere for a 1JZ with stock internals is 600HP? All help/advice greatly appreciated! Cheers. Pete Quote Link to comment Share on other sites More sharing options...
Tom Posted February 26, 2009 Share Posted February 26, 2009 (edited) You know what I'd go for as on tech2 they say another 60kg with the 1jz over the front end iirc (which I'd dought would feel that different on the road to the average driver) a track car will i'm sure feel different but I would think with the track setup you'll be going with that you could dial this extra weight out with corner weight balancing & spring rates? if i'm talking bs someone please let me know and correct me Edited February 26, 2009 by Tom (see edit history) Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 26, 2009 Author Share Posted February 26, 2009 You know what I'd go for as on tech2 they say another 60kg with the 1jz over the front end iirc (which I'd dought would feel that different on the road to the average driver) a track car will i'm sure feel different but I would think with the track setup you'll be going with that you could dial this extra weight out with corner weight balancing & spring rates? if i'm talking bs someone please let me know and correct me I'm with you on that one! The other consideration is the Tech2 demo car is fully loaded with interior, ICE etc so I'm hoping the stripped out interior, fibreglass panels and lexan instead of glass with correct corner weighting and spring rates will balance everything out! The 1JZ I am looking at is also the earlier non VVT-i version so that may save a couple more Kilos! Pete Quote Link to comment Share on other sites More sharing options...
safcdixon Posted February 26, 2009 Share Posted February 26, 2009 hello m8 im doing a jz2 gte conversion on my rex too tech2 have made its so easy its just sourcing parts realy im going with the 2jz and r154 as you are, i was going to try and make it auto but to much wiring and swapping etc mines going to be a road going single turbo beast how much would you expect to pay for the 154 gearbox btw? Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 26, 2009 Author Share Posted February 26, 2009 hello m8 im doing a jz2 gte conversion on my rex too tech2 have made its so easy its just sourcing parts realy im going with the 2jz and r154 as you are, i was going to try and make it auto but to much wiring and swapping etc mines going to be a road going single turbo beast how much would you expect to pay for the 154 gearbox btw? Hi and welcome to the forum by the way! The R154 is not rare and was fitted to a few odd cars namely: MK III Supra Turbo (not n/a version I believe?), Soarer (prime candidate for me as it comes with the 1JZ as well so could get both in one purchase!) and a few others as well. Have seen one go on fleabay for £300 so around that price for the box and £500/600 for the 1JZ hopefully which is less than the 2JZ alone! PM me as you go mate and if you need to run anything past me feel free to get in touch as more than happy to help! All the best with it! Pete Quote Link to comment Share on other sites More sharing options...
Peter P Posted February 26, 2009 Author Share Posted February 26, 2009 Have you actually bought your conversion kit from Tech2 already then mate? Would be good to have a peek if I coud to see what the quality etc is like if that's possible? Know you're a fare distance away but could arrange something I reckon! Not ordered mine as the exchange rate is so awful at the moment with the pound/dollar! Do you need to confirm the engine your going with when you order or does the one kit do both the 1/2JZ engines?? If you haven't got yours yet then ignore me!!! Cheers. Pete Quote Link to comment Share on other sites More sharing options...
safcdixon Posted February 26, 2009 Share Posted February 26, 2009 Not ordered mine as the exchange rate is so awful at the moment with the pound/dollar! Do you need to confirm the engine your going with when you order or does the one kit do both the 1/2JZ engines?? Cheers. Pete na aint bought it yet aswell as all the other stuff i need from them as u say pound is down to 1.4 i think and with any luck it will go back up i believe the same kit does both engines , i was hopeing to get the engine box loom etc 1st so i can get them refurbed rebuilt and painted with any luck it should be done for august ish there is a video on you tube ov there kit and ya can buy the conversion dvd from http://www.drifting.com think with postage mine was $32 but it aint turned up yet been 3 weeks now Quote Link to comment Share on other sites More sharing options...
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